Final Baseline Hydrology Report - October 2012 - Urban Drainage ...

More documents

Recommendations

Info

Sanderson Gulch Major Drainageway Plan Baseline Hydrology Report October 2012 LIST OF TABLES Table 1-1 Project Participants .......................................................................................................................... 2 Table 2-2 Major Crossing Structure Inventory ............................................................................................... 15 Table 2-3 Existing Drop Structure Inventory .................................................................................................. 16 Table 3-1 Subbasin Delineation Summary .................................................................................................... 27 Table 3-2 One-Hour Point Rainfall Depths (Inches) ...................................................................................... 28 Table 3-3 Zoning-Based Impervious Summary ............................................................................................. 29 Table 3-4 Manning's Roughness Coefficients & Comparison ....................................................................... 30 Table 3-5 Peak Discharge and Runoff Volume Summary (Selected Locations) .......................................... 31 Table 3-6 Comparison to Previous Studies ................................................................................................... 32 Appendix B – Hydrologic Analysis Table B-1 Table B-2 Table B-3 Table B-4 Table B-5 Table B-6 Table B-7 Table B-8 Model Development and Calibration Results ......................................................... Appendix B 1972 Sanderson Gulch MDP 100-year 2-hour Rainfall Distribution ....................... Appendix B Design Storm Distribution Comparison .................................................................. Appendix B Design Storm Depth Comparison ........................................................................... Appendix B CUHP Input Parameters - Corrected (Baseline) Hydrology Model ........................ Appendix B Detention Pond Stage-Storage-Discharge Information .......................................... Appendix B SWMM Input/Output ............................................................................................... Appendix B Peak Discharges and Runoff Volumes (All Design Points) .................................... Appendix B LIST OF FIGURES Figure 2-1 Jurisdiction Map ...................................................................................................................... 15 Figure 2-2 City-Owned Parcels Map ........................................................................................................ 16 Figure 2-3 Parks and Open Space Map ................................................................................................... 17 Figure 2-4 Irrigation Ditches Map ............................................................................................................. 18 Figure 2-5 Reach Definition Map .............................................................................................................. 19 Figure 2-6 Existing Crossings Map .......................................................................................................... 20 Figure 2-7 Drop Structures Map ............................................................................................................... 21 Appendix B – Hydrologic Analysis Figure B-1 Figure B-2 Figure B-3 Figure B-4 Figure B-5 Figure B-6 Figure B-7 Interactive Hydrology Map ...................................................................................... Appendix B Calibrated Detention Pond Inflow/Outflow .............................................................. Appendix B Watershed Boundary and 100-Yr, I-Hour Isopluvial Map ....................................... Appendix B SWMM Routing Schematic ..................................................................................... Appendix B Storm Hydrographs at Key Design Points .............................................................. Appendix B Peak Discharge vs. Location .................................................................................. Appendix B Modeled Detention Ponds and Split Flows ............................................................. Appendix B Appendix E – Environmental Assessment Figure E-1 Figure E-2 Wetland and Riparian Inventory ............................................................................. Appendix E Historical Landfills ................................................................................................... Appendix E
Sanderson Gulch Major Drainageway Plan Baseline Hydrology Report October 2012 1.0 INTRODUCTION 1.1 Authorization Matrix Design Group, Inc. (Matrix) has been retained to complete a Major Drainageway Plan (MDP) and a Flood Hazard Area Delineation (FHAD) study for the Sanderson Gulch watershed including the tributaries of North Sanderson Gulch and Mississippi Gulch. The project is co-sponsored by the Urban Drainage and Flood Control District (UDFCD), the City of Lakewood (Lakewood) and the City and County of Denver (Denver). The Agreement regarding the Major Drainageway Plan (MDP) and Flood Hazard Area Delineation (FHAD) study for Sanderson Gulch (Agreement No. 12-04.04) was executed on July 12, 2012. 1.2 Purpose and Scope The purpose and scope of this project is to develop an updated Major Drainageway Plan (MDP) for the Sanderson Gulch watershed (Study Area). The Urban Drainage & Flood Control District was formed in 1969 and Sanderson Gulch was one of the first watersheds to be master planned in 1972. The original MDP for the Study Area is entitled Major Drainageway Planning, Sanderson Gulch/Weir Gulch (Frasier & Gingery, August 1972). The former FHAD for the Study Area is Flood Hazard Area Delineation, Sanderson Gulch and North Sanderson Gulch (Gingery Associates, Inc., August 1979). Major elements of the scope of work for the current project are as follows: • Gather and assemble available information on existing drainage facilities, planning studies, land use plans, zoning, land ownership and other relevant information. • Coordinate with project sponsors including preparing for and participating in project meetings and public outreach meetings. • Develop updated hydrologic modeling for the entire watershed in accordance with current UDFCD modeling criteria. • Develop updated hydraulic modeling for all of Sanderson Gulch and North Sanderson Gulch. • Assess deficiencies in existing road crossings. • Assess deficiencies in existing grade controls and determine if and where new grade control structures are needed. • Assess deficiencies and failures in channel banks. • Evaluate alternative solutions to identified problems. • Evaluate options to import Mississippi Gulch major storm flows into Sanderson Gulch. (The minor storm is currently piped from Mississippi Gulch to Sanderson Gulch). • Develop an updated master plan for improvements including costs that address identified deficiencies and needs. • Develop an updated MDP report that documents all work completed and the selected improvements plan. 1.3 Planning Process Project sponsors consist of the following: • Urban Drainage and Flood Control District • City and County of Denver • City of Lakewood Participants from the project sponsors are listed in Section 1.6 Acknowledgements. A project advisory committee consisting of representatives from the project sponsors held a kickoff meeting on July 17, 2012 at the offices of UDFCD. Progress meetings with the advisory committee were subsequently held August 21 and October 15, 2012 (see enclosed Meeting Minutes in Appendix A: Project Correspondence). Additional progress meetings will be held on an approximate monthly basis throughout the study process. Public meetings are planned for this project, but have not yet occurred, to gather input from residents, stakeholders and interested parties. Dates for those meetings will be documented in the meeting minutes provided in the Appendix A. 1.4 Mapping and Surveys Mapping information for this project was obtained from several sources. Given the multi-jurisdictional makeup of the watershed, every attempt was made to use the best available data. The following describes the various mapping components and their sources. Topographic Contours Two-foot topographic LIDAR-derived contour data collected by the USGS in the spring of 2008 was used for the eastern half of the watershed. The area along the drainageway for the west portion of the watershed was flown by TransVision in May 2012 which produced 2-foot contour data. USGS 10 meter DEM data were used to supplement the remaining area outside the Gulch corridor in the western half of the basin. Aerial Photography A 2009 color aerial photo, with a one foot pixel resolution, was provided by UDFCD. Base Mapping Base mapping information including, street centerlines, parcels, zoning, jurisdictional boundaries, and park boundaries were provided by the City and County of Denver and the City of Lakewood. Crossing Structure Survey Field survey of all existing road crossings was completed in June 2012 by Accurate EngiSurv, LLC and provided by UDFCD. Denver provided sufficiency ratings for the bridges within their jurisdiction. Coordinate System and Datum All GIS mapping and data for this study were developed using the Colorado State Plane, Central Zone coordinate system in U.S. feet. The horizontal datum is NAD83 and the vertical datum is NAVD88. 1
Page 1 and 2: S A N D E R S O N G U L C H Major D
Page 3: Sanderson Gulch Major Drainageway P
Page 7 and 8: Sanderson Gulch Major Drainageway P
Page 25 and 26: S Lee St S Allison St S Pierce St S
Page 27 and 28: S Lee St S Allison St S Pierce St h
Page 29 and 30: S Lee St S Allison St S Pierce St S
Page 41 and 42: Sanderson Gulch Meeting Minutes Jul
Page 43 and 44: Sanderson Gulch Minutes August 21,
Page 45 and 46: Sanderson Gulch Meeting Minutes Oct
Page 53: Sanderson Gulch Major Drainageway P
Page 58 and 59:
2109 2304 2107 2105 2302 2103 !( !(
Page 60 and 61:
2165 2204T 2155 2149 2146 !( #* #*
Page 62 and 63:
Sanderson Gulch Major Drainageway P
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
DRAINAGE CRITERIA MANUAL (V. 1) RUN
Page 100 and 101:
RUNOFF DRAINAGE CRITERIA MANUAL (V.
Page 102 and 103:
STORM DRAINAGE DESIGN AND TECHNICAL
Page 105 and 106:
Page 107:
S Lee St S Allison St S Pierce St L
show all

Final Baseline Hydrology Report - October 2012 - Urban Drainage ...

Create successful ePaper yourself

Delete template?

Save as template?